Genetic contributions to the educational inequalities in coronary heart disease incidence: a population-based study of 32 000 middle-aged men and women

Background The background of educational disparities in coronary heart disease (CHD) risk is still not well understood. We used a polygenic score for education (PGS EDU ), socioeconomic indicators and indicators of CHD risk to investigate whether these disparities result from causality or are influenced by shared factors. Methods Population-based health surveys including baseline measures on cardiometabolic risk factors at 25–70 years of age (N=32 610) and PGS EDU were conducted in Finland between 1992 and 2011. Longitudinal information on education, social class, income and CHD incidence (1716 CHD cases up to 2019) was based on national registers. Linear regression, Poisson regression, Cox regression and linear structural equation models were used. Results Education and PGS EDU were inversely associated with body mass index, systolic and diastolic blood pressure, total cholesterol and CHD incidence and positively associated with high-density lipoprotein cholesterol in men and women. Part of the associations of PGS EDU with CHD incidence (57% in men and 28% in women) and cardiometabolic factors (30%–55% and 31%–92%, respectively) were mediated by education, social class and income, but a substantial part of them was independent of socioeconomic factors. These associations were consistent across different levels of education. Conclusions PGS EDU captures CHD risk that is not solely attributable to education and other socioeconomic indicators. This suggests that not only causality affects the educational disparities of CHD risk but also factors reflected by PGS EDU can contribute to them. Identifying these factors can help to understand and reduce socioeconomic health disparities.